Determination of the Structure of the Atmosphere between 90 and 250 km by means of Contaminant Releases at Woomera, May 1968
17 Feb 1972-Philosophical Transactions of the Royal Society A (The Royal Society)-Vol. 271, Iss: 1218, pp 631-663
TL;DR: In this article, a series of measurements of neutral atmospheric wind velocity, turbulent structure, temperature and density were made during each launch between 90 and 250 km altitude, combining the experimental techniques of the two groups involved.
Abstract: Two Skylark rockets were launched from Woomera rocket range, Australia (31 degrees S) on the morning and evening of 31 May 1968. Coordinated series of measurements of neutral atmospheric wind velocity, turbulent structure, temperature and density were made during each launch between 90 and 250 km altitude, combining the experimental techniques of the two groups involved. This paper attempts to construct from the combined measurements made on these occasions a dynamic picture of the interactions of atmospheric structure, and to relate the observations to previous results obtained by ourselves and other workers.
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TL;DR: In this article, the authors derived expressions for the low-frequency part of the fractional pressure variations in the E-region of the ionosphere under the stated perturbed condition may be considered to be manifested through Lorentzforce and Joule-dissipation that influence the neutral gas of the atmosphere via collision-mechanism and thereby gravity waves are launched.
Abstract: Generation of short-range gravity waves within the ionosphere due to inhomogenous heating in the presence of space-localized inhomogeneities during high-power radio wave-propagation has been investigated. The magnitude and from of the anticipated atmospheric wave-trains are obtained. The derived experession of electric field within the ionosphere under the stated perturbed condition may be considered to be manifested through Lorentz-force and Joule-dissipation that influence the neutral gas of the atmosphere via collision-mechanism and thereby gravity waves are launched. The expressions for the low-frequency part of the fractional pressure variations have been derived which are applied to theE-region of the ionosphere. The results are presented graphically.
1 citations
01 Jan 2011
TL;DR: In this paper, the authors investigated the reliability of the spectral-width method used by radars to determine turbulence and compared it with in-situ measurements of high-resolution research and commercial aircraft.
Abstract: This thesis focuses on the investigation of the reliability of turbulence measurements by radars when the spectral-width method is used. This method employs the spectral widths observed by radar (experimental spectral width) to determine turbulence. However, the experimental width can be a ected by non-turbulent e ects, including radar geometry. Therefore, the spectral width due to non-turbulent e ects (theoretical spectral width) must be removed from the experimental width. This can occasionally lead to negative values of turbulence. It is our aim (1) to study the e ects of both experimental and theoretical spectral widths on the accuracy of turbulence measurements, (2) to study the validity of negative values of turbulence, and (3) to compare radar-estimated values of turbulence with in-situ measurements. This is performed by studying the factors that can contribute to errors in estimation of spectral widths, including mean wind speed, wind shear, anisotropy and length of data. In addition to that, radar-estimated turbulence is compared to turbulence measured by high-resolution research and commercial aircraft. Signi cant ndings include: 1. The statistical uctuations of mean wind speed and its impact on estimation of the theoretical spectral width is the most important factor in producing errors in turbulence measurements. 2. The choice of spectrum tting algorithm and length of data is very important in producing experimental spectral widths. 3. In order to estimate theoretical widths more accurately, a formula is developed by comparing models that calculate the theoretical spectral width. 4. It is found that both negative and positive values of turbulence need to be included in turbulence analysis. However, if the percentage of negatives exceeds 35%, the measurements are not reliable. 5. Turbulence data measured by radar agrees well with high-resolution aircraft data for weak turbulence. However, in-situ aircraft measurements show a higher probability of strong turbulence than hourly radar data. 6. The theoretical spectral width is small compared to the experimental one for strong turbulence. By discarding the theoretical spectral widths in turbulence
1 citations
01 Jan 1996
TL;DR: The Earth's atmosphere is an open system far from thermal equilibrium as discussed by the authors, which can spontaneously form spatio-temporal patterns in contrast to closed systems in thermal equilibrium whose macroscopic states are spatially homogeneous and time-independent.
Abstract: The Earth’s atmosphere is an open system far from thermal equilibrium. It is irradiated by the shortwave radiation of the sun, emits radiation in the infrared and continuously exchanges matter, energy and momentum with the cryosphere, the hydrosphere, the biosphere and the lithosphere. Systems far form equilibrium can spontaneously form spatio-temporal patterns in contrast to closed systems in thermal equilibrium whose macroscopic states are spatially homogeneous and time-independent. This latter behaviour is a consequence of the second law of thermodynamics and was formulated in the last century as the “heat death of the universe”.
TL;DR: The motion of vapour clouds released into the upper atmosphere appears, in most cases, to be satisfactorily explained by assuming they take up those of the ambient atmosphere, but down-leg releases occasionally show anomalies which have yet to be explained as discussed by the authors.
TL;DR: In this paper, the gradient coupling within the ionospheric plasma in the presence of local variation of atmospheric heating and other modifications during high power radio wave propagation has been studied and the appropriate form of coupled equations for the modified situation is obtained.
Abstract: The gradient coupling within the ionospheric plasma in the presence of local variation of atmospheric heating and other modifications during high power radio wave propagation has been studied The appropriate form of coupled equations for the modified situation is obtained The electromagnetic and acoustic modes of wave propagation have been separated and solved, by the WKB method Field quantities may be used to explore different properties of the medium under the modified condition
References
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Book•
01 Jan 1954
TL;DR: Molecular theory of gases and liquids as mentioned in this paper, molecular theory of gas and liquids, Molecular theory of liquid and gas, molecular theories of gases, and liquid theory of liquids, مرکز
Abstract: Molecular theory of gases and liquids , Molecular theory of gases and liquids , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
11,807 citations
Book•
01 Jan 1953
TL;DR: In this article, the kinematics of the field of homogeneous turbulence and the universal equilibrium theory of decay of the energy-containing eddies are discussed. But the authors focus on the dynamics of decay and not on the probability distribution of u(x).
Abstract: Preface 1 Introduction 2 Mathematics representation of the field of turbulence 3 The kinematics of homogeneous turbulence 4 Some linear problems 5 General dynamics of decay 6 The universal equilibrium theory 7 Decay of the energy-containing eddies 8 The probability distribution of u(x) Bibliography of research on homogeneous turbulence Index
3,121 citations
TL;DR: In an earlier paper as mentioned in this paper, values of exospheric density were obtained from the orbit of Echo 2 for the years 1964-1965, and the results indicated a semi-annual variation in density by a factor of between 2 and 3, considerably larger than predicted by existing atmospheric models.
17 citations
15 citations